Black Raspberries as Treatment for Cancer?

The pigmentation chemical that makes grape skins and wines red has been found to kill human leukemia and lymphoma cells cultured in a lab. These results must be confirmed in further animal and human studies.

The colorful pigment found in raspberries, strawberries, grapes, and cherries may offer significant protection against cancer in general and may also aid in treating tumors. According to research published in the Journal of Biological Chemistry, the pigmentation chemical that makes grape skins and wines red has been found to kill human leukemia and lymphoma cells cultured in a lab. These results must be confirmed in further animal and human studies.

McGowan Institute faculty member Xiao-Ming Yin, MD, PhD, associate professor in the University of Pittsburgh's department of pathology, member of the Comprehensive Cancer Center and member of the Biomedical Graduate Program, and also the associate director, division of molecular diagnostics in the department of pathology at Presbyterian-Shadyside Hospital, reported that black raspberry extract killed leukemia cells in cultures while sparing healthy cells.

"Current treatments for leukemia, such as chemotherapy and radiation, often damage healthy cells and tissues and can produce unwanted side effects for many years afterward," said study coauthor Dr. Yin. "So, there is an intensive search for more targeted therapies for leukemia worldwide."

For this latest experiment, Yin and his team studied the effects and the mechanisms of cyanidin-3-rutinoside (C-3-R)-a water-soluble flavonoid that provides color to flowers, leaves, fruits, and vegetables-to see how it behaves in the presence of cancer. The C-3-R was extracted and purified from black raspberries, though it also abounds in red wine, and was used in much higher amounts than the typical red wine drinker would be able to consume.

The C-3-R was tested on several lines of human leukemia and repeated using cell cultures of lymphoma, another immune system-based cancer. The scientists observed that, at low doses of C-3-R, half of the cancer cells in all of the lines died within 18 hours of treatment. At higher doses, the C-3-R killed all of the cells by the end of the 18-hour period. The experiment was repeated several times, on different types of leukemia cancer cells, with similar results.

Yin's team found that C-3-R caused the cells to produce peroxides, a type of free radical that, in turn, activated a pathway within the cancer cells that caused them to die. In contrast, when the researchers treated normal human blood cells with C-3-R, they did not find any increased accumulation of free radicals and there were no apparent toxic effects on these cells.

"Therefore, if we can reproduce these anticancer effects in animal studies," Dr. Yin said, "this will present a very promising approach for treating a variety of human leukemias and, perhaps, lymphomas as well."